Wireless system



March 24, 1925.

; 1,531,203 0. LU NDQUIST WIRELESS SYSTEM- Filed July 25, v19.22

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CLIFFORD LUHDQUIST- Patented Mar. 24,1

I A p Y PATENT or ice a-reca wmm Application filed July 25,

t which the following is a Specification.

This invention relates to wireless trans mission of intelligence and has special reference toapparatuses for transmitting telegraphic signals on wireless telephone circuits. t

The principal object of the invention is to provide an improved. and simplearrange. ment of apparatus for the purpose set forth. I

A second important object of the inven-; tion is to, provide an improved form of telephonic transmitter" for i use in connection with the sending of wireless telepraphic signa 5.

A third important object of the invention is toprovide novel means for damping the vibrations of the diaphragm in such a telephonic transmitter; I

With the above and other objects in view, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings, and specifically claimed.

a In the accompanying drawings, like characters ofreference indicate like parts in the several views, and

Figure 1 is a. diagrammatical view of the hook up for the apparatus in a simple and typical form. t t j I a a Figure 2 is a transverse: section through the telephonic transmitter used herewith and showing the damping means.

I Figure 3 is a front view of said transmitter with a portion of the casing broken away to show the damping means.

In carrying out the objects of the invention a simple form of hook up has been disclosed which embodies the primary circuit A, secondary circuitBf and aerial circuit C. The circuits B and C are of the ordinary form and will not be described in detail exce'pt to saythat circuit B receives its cur- I0 vided a source 0 power 11 which is here in- IOWA- wmELEsssYs'rEM. Y

1922. Serial No. 577,386.

dicated as a direct current generator, al-

though any other suitable source of power may be utilized. In series with the source 11 is a receiver 12 the construction of which will be hereinafter set forth, a transmitter .18 and a telegraphickey 14:. Also. connected in series with the-source 11 is a motor driveninterrupter 15 and a variable resistance 16. The line through the interrupter and resistance is connected to one pole of the primary of the transformer 10, the other line being connected tothe other pole of said transformer primary. lVith this circuit it will be noted that the interrupter is driven a. very high rate of speed so that the interruptions pass beyond the audible range and it is to this end that a direct current and interrupter are preferred to theusual alternating current generator. This arrangement produces a harmonic sound of greater intensity and the tone can be changed by varying the resistance 16 or by utilizing the peculiar construction of the receiver 12.

This receiver 12 comprises the usual casing 17 wherein are electromagnets l8 having an armature in the form of a diaphragm 19. Secured to one side of the casing is a bracket 2O carrying on its extremity a nut '21 wherethrough passes an adjusting screw 22 having swivelled connection to a dampener 23 of felt, rubber, or the like and whichrests against the diaphragm 19. The position of this dampener may be shifted radially of the diaphragm by turning the screw 22 as shown in Figure 2. Whenever the dan pener is moved toward the center of the diaphragm a greater effect will be obtained than when it is moved toward the periphery of said diaphragm and in this manner the vibration of the diaphragm can be controlled.

There has thus been provided a simpleand eflicient device of the kind described and for the purposesspecified.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material principles thereof. It is not therefore desired to confine the invention to the exact form herein shown and. described, but it is wished to include all such as properly come within the scope claimed.

Having thus described the invention what arranged to move the damper radially of the 1 is claimed as new, is diaphragm.

In a receiver of the class described, a cas- In testimony whereof I aflix my signature ing a diaphragm forming anarmature, a in presence oftwowitnesses. w 1 5 bracket'carried by said casing and provided with a nut on its extremity, a screw extend- CLIFFORD LUNDQUiST. ing through said nut, and a damperiswiv- \Vitnesses: elled to said screw and transversing said G. W. DAMMON',

diaphragm, said bracket and screw being v R."ARTLAND. 

